This invention relates to techniques for data manipulation and building control for forming three-dimensional (3D) objects, more particularly it relates to techniques for use in Rapid Prototyping and Manufacturing (RPandM) Systems and most particularly to data manipulation and building control methods and apparatus for use in a Thermal Stereolithography (TSL) system, Fused Deposition Modeling (FDM) system, or other Selective Deposition Modeling (SDM) system.
Various approaches to automated or semi-automated three-dimensional object production or Rapid Prototyping and Manufacturing have become available in recent years, characterized in that each proceeds by building up 3D objects from 3D computer data descriptive of the objects in an additive manner from a plurality of formed and adhered laminae. These laminae are sometimes called object cross-sections, layers of structure, object layers, layers of the object or simply layers (if the context makes it clear that solidified structure of appropriate shape is being referred to). Each lamina represents a cross-section of the three-dimensional object. Typically lamina are formed and adhered to a stack of previously formed and adhered laminae. In some RPandM technologies, techniques have been proposed which deviate from a strict layer-by-layer build up process wherein only a portion of an initial lamina is formed and prior to the remaining portion(s) of the initial lamina at least one subsequent lamina is at least partially formed.
According to one such approach, a three-dimensional object is built up by applying successive layers of unsolidified, flowable material to a working surface, and then selectively exposing the layers to synergistic stimulation in desired patterns, causing the layers to selectively harden into object laminae which adhere to previously-formed object laminae. In this approach, material is applied to the working surface both to areas which will not become part of an object lamina, and to areas which will become part of an object lamina. Typical of this approach is Stereolithography (SL), as described in U.S. Pat. No. 4,575,330, to Hull. According to one embodiment of Stereolithography, the synergistic stimulation is radiation from a UV laser, and the material is a photopolymer. Another example of this approach is Selective Laser Sintering (SLS), as described in U.S. Pat. No. 4,863,538, to Deckard, in which the synergistic stimulation is IR radiation from a CO2 laser and the material is a sinterable powder. A third example is Three-dimensional Printing (3DP) and Direct Shell Production Casting (DSPC), as described in U.S. Pat. Nos. 5,340,656 and 5,204,055, to Sachs, et al., in which the synergistic stimulation is a chemical binder, and the material is a powder consisting of particles which bind together upon selective application of a chemical binder.
According to a second such approach, an object is formed by successively cutting object cross-sections having desired shapes and sizes out of sheets of material to form object lamina. Typically in practice, the sheets of paper are stacked and adhered to previously cut sheets prior to their being cut, but cutting prior to stacking and adhesion is possible. Typical of this approach is Laminated Object Manufacturing (LOM), as described in U.S. Pat. No. 4,752,352, to Feygin in which the material is paper, and the means for cutting the sheets into the desired shapes and sizes is a CO2 laser. U.S. Pat. No. 5,015,312 to Kinzie also addresses LOM.
According to a third such approach, object laminae are formed by selectively depositing an unsolidified, flowable material onto a working surface in desired patterns in areas which will become part of an object laminae. After or during selective deposition, the selectively deposited material is solidified to form a subsequent object lamina which is adhered to the previously-formed and stacked object laminae. These steos are then repeated to successively build up the object lamina-by-lamina. This object formation technique may be generically called Selective Deposition Modeling (SDM). The main difference between this approach and the first approach is that the material is selectively deposited only in those areas which will become part of an object lamina. Typical of this approach is Fused Deposition Modeling (FDM), as described in U.S. Pat. Nos. 5,121,329 and 5,340,433, to Crump, in which the material is dispensed while in a flowable state into an environment which is at a temperature below the flowable temperature of the material, and which then hardens after being allowed to cool. A second example is the technology described in U.S. Pat. No. 5,260,009, to Penn. A third is Ballistic Particle Manufacturing (BPM), as described in U.S. Pat. Nos. 4,665,492; 5,134,569; and 5,216,616, to Masters, in which particles are directed to specific locations to form object cross-sections. A fourth example is Thermal Stereolithography (TSL) as described in U.S. Pat. No. 5,141,680, to Almquist et. al.
When using SDM (as well as other RPandM building techniques), the appropriateness of various methods and apparatus for production of useful objects depends on a number of factors. As these factors cannot typically be optimized simultaneously, a selection of an appropriate building technique and associated method and apparatus involve trade offs depending on specific needs and circumstances. Some factors to be considered may include 1) equipment cost, 2) operation cost, 3) production speed, 4) object accuracy, 5) object surface finish, 6) material properties of formed objects, 7) anticipated use of objects, 8) availability of secondary processes for obtaining different material properties, 9) ease of use and operator constraints, 10) required or desired operation environment, 11) safety, and 12) post processing time and effort.
In this regard there has been a long existing need to simultaneously optimize as many of these parameters as possible to more effectively build three-dimensional objects. As a first example, there has been a need to enhance object production speed and lower set up time and file preparation time when building objects using a Selective Deposition Modeling technique (SDM) as described above (e.g. Thermal Stereolithography) while simultaneously maintaining or reducing the equipment cost. A critical problem in this regard has been the need for an efficient technique for generating and handling build data. Another critical problem involves the need for an efficient technique for generating support data appropriate for supporting an object during formation. Additional problems involve the existence of control software which is capable of manipulating the massive amounts of data involved in real time, of compensating for jet misfiring or malfunctioning, of adjusting data so it is accessible in the order needed, and for efficiently providing geometry sensitive build styles and deposition techniques. Appropriate build styles and support structures for use in SDM for which a data generation technique is needed are described in U.S. patent application Ser. No. 08/534,813, now abandoned.
Accordingly, there is a long-felt but unmet need for methods and apparatus to derive data and control an SDM system to overcome the disadvantages of the prior art.
All patents referred to in this section of the specification are hereby incorporated by reference as if set forth in full.
The following applications are hereby incorporated herein by reference as if set forth in full herein:
The assignee of the subject application, 3D Systems, Inc., is filing this application concurrently with the following related application, which is incorporated by reference herein as though set forth in full:
According to Thermal Stereolithography and some Fused Deposition Modeling techniques, a three-dimensional object is built up layer by layer from a material which is heated until it is flowable, and which is then dispensed with a dispenser. The material may be dispensed as a semi-continuous flow of material from the dispenser or it may alternatively be dispensed as individual droplets. In the case where the material is dispensed as a semi-continuous flow it is conceivable that less stringent working surface criteria may be acceptable. An early embodiment of Thermal Stereolithography is described in U.S. Pat. No. 5,141,680, which is hereby incorporated by reference. Thermal Stereolithography is particularly suitable for use in an office environment because of its ability to use non-reactive, non-toxic materials. Moreover, the process of forming objects using these materials need not involve the use of radiations (e.g. UV radiation, IR radiation, visible light and/or laser radiation), heating materials to combustible temperatures (e.g. burning the material along cross-section boundaries as in some LOM techniques), reactive chemicals (e.g. monomers, photopolymers) or toxic chemicals (e.g. solvents), complicated cutting machinery, and the like, which can be noisy or pose significant risks if mishandled. Instead, object formation is achieved by heating the material to a flowable temperature then selectively dispensing the material and allowing it to cool.
U.S. patent application Ser. No. 08/534,813, now abandoned, is directed primarily to Build and Support styles and structures which can be used in a preferred Selective Deposition Modeling (SDM) system based on TSL principles Alternative build and support styles and structures are also described for use in other SDM systems as well as for use in other RPandM systems.
U.S. patent application Ser. No. 08/535,772, now abandoned, is directed to the preferred material used by the preferred SDM/TSL system described hereinafter. Some alternative materials and methods am also described.
U.S. patent application Ser. No. 08/534,447, now abandoned, is a parent application for the instant application and is directed to data transformation techniques for use in converting 3D object data into support and object data for use in a preferred Selective Deposition Modeling (SDM) system based on TSL (thermal stereolithography) principles. This referenced application is also directed to various data handling, data control, and system control techniques for controlling the preferred SDM/TSL system described hereinafter. Alternative data manipulation techniques and control techniques are also described for use in SDM systems as well as for use in other RPandM systems.
The assignee of the instant application, 3D Systems, Inc., is also the owner of a number of other U.S. patent applications and U.S. patents in RPandM field and particularly in the Stereolithography portion of that field. The following commonly owned U.S. patent applications and U.S. patents are hereby incorporated by reference as if set forth in full herein.
The instant invention embodies a number of techniques (methods and apparatus) that can be used alone or in combination to address a number of problems associated with data generation, data handling and system control for use in forming 3D objects by Selective Deposition Modeling. Though primarily directed to SDM techniques, the techniques described hereinafter can be applied in a variety of ways to the other RPandM technologies as described above to enhance system throughput by providing enhanced data manipulation and generation techniques. Furthermore, the techniques described herein can be applied to SDM systems that use one or more building and/or support materials wherein one or more of the materials are selectively dispensed, wherein others may be dispensed non-selectively, and wherein elevated temperatures may or may not be used for all or part of the materials to aid in their selectively deposition.
The techniques can be applied to SDM systems wherein the building material (e.g. paint or ink) is made flowable for dispensing purposes by adding to it a solvent (e.g. water, alcohol, acetone, paint thinner, or other solvents appropriate for specific building materials), which material can be made to solidify after dispensing by causing the removal of the solvent (e.g. by heating the dispensed material, by dispensing the material into a partially evacuated (i.e. vacuum) building chamber, or by simply allowing sufficient time for the solvent to evaporate). Alternatively and/or additionally, the building material (e.g. paint) may be thixotropic in nature wherein an increase in shear force on the material could be used to aid its dispensing or the thixotropic property may simply be used to aid the material in holding its shape after being dispensed. Alternatively and/or additionally, the material may be reactive in nature (e.g. a photopolymer, a thermal polymer, a one or two-part epoxy material, a combination material such as one of the previously mentioned materials in a combination with a wax or thermal plastic material) or at least solidifiable when combined with another material (e.g. plaster of paris and water) wherein after dispensing the material is reacted by appropriate application of prescribed stimulation (e.g. heat, EM radiation (visible, IR, UV, x-rays, etc.), a reactive chemical, the second part of a two part epoxy, the second or multiple part of a combination) wherein the building material and/or combination of materials become solidified. Of course, Thermal Stereolithographic materials and dispensing techniques may be used alone or in combination with the above alternatives. Furthermore, various dispensing techniques may be used such as dispensing by single or multiple ink jet devices including hot melt ink jets, bubble jets, etc. and continuous or semi-continuous flow, single or multiple orifice extrusion nozzles or heads.
A first object of the invention to provide a method and apparatus for converting three-dimensional object data into cross-sectional data.
A second object of the invention is to provide a method and apparatus for production of objects including a method and apparatus for converting three-dimensional object data into cross-sectional data.
A third object of the invention to provide a method and apparatus for obtaining support data from three-dimensional object data.
A fourth object of the invention is to provide a method and apparatus for production of objects including a method and apparatus for obtaining support data and using the support data during object formation.
It is intended that the above objects can be achieved separately by different aspects of the invention and that additional objects of the invention will involve various combinations of the above independent objects such that synergistic benefits may be obtained from combined techniques.
Other objects of the invention will be apparent from the description herein.